Voltage and/or current sensing devices in medium voltage networks in the state of the art might be easily standardized in their parameters and they can achieve high measuring accuracy, in case the electronic devices which are connected to the sensing devices enable the use of correction or calibration factors. These factors are specific to each single sensing device, calculated and/or measured during routine tests of these devices. These factors then need to be mentioned on a label of such devices and during installation of these devices, the factors need to be manually inserted into software of the connected electronic device. As there might be several digit numbers used as a calibration factor, it is not so difficult to make a mistake in writing the number into software of the electronic device, thus resulting in incorrect information processed within the measuring device. The same can happen in the case when the correction/calibration factor is integrated into an actual transformation/division ratio of a given device. In this case the actual transformation ratio might be a number of several digits that must be manually inserted into a connected electronic device and mistakes can easily occur during this process.
All electronic elements which are necessary for the aforesaid purpose are installed normally in a separate electronic calculation and display device.
Sensors are elements, which are to be calibrated, and each sensor needs its own set of calibration parameters or actual transformation ratio. So the central electronic calculation unit has to consider each individual sensor parameter set. So the accuracy of such sensors, depends on the effectively of such parameter and data accuracy.